This invention relates generally to injection devices for use with an external infusion system for subcutaneous delivery of a selected medication or other therapeutic fluid to a patient. More particularly, this invention relates to an improved subcutaneous injection set for quick and easy transcutaneous placement of a soft cannula through the skin of a patient at a selected medication infusion site.
Subcutaneous injection sets are generally known in the medical arts for use in the administration of a selected medication or other therapeutic fluid to a desired subcutaneous infusion site located beneath the skin of a patient. Such injection set commonly includes a tubular cannula or catheter which is supported by and protrudes from a compact housing adapted to receive the infusion fluid via delivery or infusion tubing which is suitably connected to other components of the fluid infusion system.
The subcutaneous injection set normally includes an insertion needle which is assembled with the soft cannula and is adapted to pierce the patient's skin for transcutaneous cannula placement. The insertion needle is thereafter withdrawn to leave the cannula in place for subcutaneous fluid infusion. Exemplary subcutaneous injection sets of this general type are described and claimed in U.S. Pat. Nos. 4,755,173; 5,176,662; and 5,257,980, which are incorporated by reference herein. Such subcutaneous injection sets are commonly used with compact medication infusion pumps for programmable administration of medication such as insulin, wherein exemplary infusion pumps of this general type are described in U.S. Pat. Nos. 4,562,751; 4,678,408; and 4,685,903, which are incorporated by reference herein.
In the past, subcutaneous injection sets have typically been constructed from multiple assembled components for receiving and supporting the infusion tubing in flow communication with the soft cannula, in combination with the insertion needle for subcutaneous cannula placement. Accordingly, while these prior injection sets have functioned in a satisfactory manner, production thereof has been relatively costly and tedious.
The present invention provides a significantly improved subcutaneous injection set which can be manufactured quickly and easily from a comparatively minimum number of parts which when assembled provide for quick and easy subcutaneous cannula placement.